This was an infraview artifact for DX3, and if I would have used WTV I would have realized there wasn't a problem. I would cut part of the texture out and replace with another, and the static part of the image would turn a blue hue, instead of looking like snow it would look like ice. One example, I was working with tree and branch textures always used the color adjust feature in infraview shift + U only to find out it wasn't consistent especially when it came to DX3 and DX5. Third party programs, third party programs tend to be inconsistent or horrible at viewing DX3 and DX5. If you have an AMD card I'm sure the viewer will sabotage one way or another. WTV (Nvidia's dds viewer) displays DDS as they would be seen in your game except for the purple transparency background if you have an Nvidia card. The best DDS viewer depends on your graphics card. The same with DDS viewer - the best is WTV which Vince mentioned - it displays all the information you may need in one place (format, size, mipmaps) and you can switch back and forth between RGB composite and alpha channel which is very very useful (shift+A or ctrl+A displays the alpha channel U switches back to RGB composite). I can agree that IrfanView is one of the best from all-arounders out there (and I still use it for few things), but there are some apps and programs that do specific things just better and faster. Of course it all depends on things you like and need to work with, but for browsing photographs (in both jpg and raw formats) FSViewer is superior in comparison to Irfan (to all the information like meta data, exif, zooming, color managed images, you can access in FSV much quicker than in Irfan). Well, to tell the truth, IrfanView was indeed my very favorite image viewer program in the past. Oh, it's not the fastest at all, Fast Stone Viewer, for instance, beats it by miles in terms of overall speed. I like it the most because it's simplest, fastest (at least it seems to me) and it has options to open draw menu, enter text.

Dds file viewer